AF Stop Button With the EOS 630/600, RT, A2/A2E/5, or 10 S /10 set to the AI Servo AF mode and continuous shooting, AF will not resume even after you let go of the AF stop button. Press the shutter release button halfway to resume AF.
Camera/Extender Compatibility Chart *2: EOS650, EOS620, EOS750, EOS750 QD, EOS850, EOS850 QD, EOS700, EOS10S/10, EOS REBEL/1000, EOS REBEL S /1000 F , EOS REBEL S QD/1000 FN QD, EOS ELAN/100, EOS630/600, EOS RT, EOS-1, EOS REBEL II/1000N, EOS A2/5